//
// Copyright (c) 2016-2018 Haggai Eran, Gabi Malka, Lior Zeno, Maroun Tork
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification,
// are permitted provided that the following conditions are met:
//
//  * Redistributions of source code must retain the above copyright notice, this
// list of conditions and the following disclaimer.
//  * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation and/or
// other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS''
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
// ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//

#pragma once

#include <axi_data.hpp>

/* Assumes in/out are AXI4-Stream (blocking read/writes) */
class drop_or_pass {
public:
    drop_or_pass() : _state(DECISION) {}

    void filter(hls::stream<bool>& decision, hls_ik::data_stream& in,
                hls_ik::data_stream& out) {
    #pragma HLS pipeline enable_flush ii=1
        switch (_state) {
        case DECISION:
            if (decision.empty())
                break;

            _pass = decision.read();

            _state = STREAM;
            /* Fall through */

        case STREAM:
            if (in.empty())
                break;

            hls_ik::axi_data d = in.read();

            if (_pass)
                out.write(d);

            if (d.last)
                _state = DECISION;

            break;
        }
    }
private:
    enum { DECISION, STREAM } _state;
    bool _pass;
};
